1. Field of the Invention
The invention relates to a robot having a navigating system capable of executing cartesian coordinate functions and doing work or producing physical reference lines or singular reference points on a plane surface traversed, such as for construction for work and position location or other layout, on a selected surface area. The robot can also record the coordinates of a path traversed for later reference and, if desired, at the time or later, leave evidence of the path traversed.
2. Description of Related Art
In the construction and manufacturing industries, long-lasting reference lines are required to insure accurate placement of equipment, center lines, interior partitions, floor penetrations, exterior sheeting and accuracy of locations or relative positions where other action is required. The customary method used, after structural members and flooring are in place, is to recall the surveyors or field engineers to establish the reference lines, usually by the transit and tape method. Reference points outside the immediate work area are extended by a transit or theodolite into the work area to establish control points. The points are then connected. This is commonly done with a chalk line to provide control lines. Permanence is provided by applying a thin coating of spray paint over the chalk line. From the control line all other required locations are established by the same transit and tape method. This method is not only labor intensive and costly in both time and man-power but, more importantly, it is subject to many opportunities for human errors in reading and interpreting the blue print, performing repeated calculations, etc., that are necessary for consistent and accurate use of the survey equipment.
The use of mobile robots is well known and several robot navigation systems are known. These include buried guide means, central radio and optical systems and on-board computers. Navigating robots have been used primarily as carrier vehicles which begin at some point and find their way, through use of either sensors or a planned path of coordinates, along corridors and rooms to a desired location for delivery of objects. Examples are U.S. Pat. Nos. 4,119,900, issued 10 Oct. 1978 to Kremnitz; 5,032,775, issued 16 Jul. 1991 to Mizuno et al; 5,073,749, issued 17 Dec. 1991 to Kanayama; 5,086,535, issued 11 Feb. 1992 to Grossmeyer et al; and 5,031,109, issued 9 Jul. 1991 to Gloton. Robots have also been made with inclinometers and cut-off switches for various reasons.
These prior navigating robots have employed left and right wheel or track differential speeds and other wheel or track maneuver means to achieve the angular orientation necessary to travel from one point to another. The required accuracy of the surveyor is difficult to achieve by using these methods of turning. Prior surveying instruments achieve the required angular orientation accuracy by using a transit or theodolite. These systems, however, are confined to operating from stationary locations such as a tripod or permanent reference "monument" fitted to receive the instrument.
Marking systems have been placed on robot means. Examples are U.S. Pat. Nos. 4,665,600, issued 19 May 1987 to Faurie et al and 5,307,272, issued 26 Apr. 1994 to Butler et al. Multi-color ink jets are known. One example is U.S. Pat. No. 4,446,470, issued 1 May 1984 to Sugiyama et al.
SUMMARY OF THE INVENTION
The present invention overcomes prior difficulties by combining the high degree of accuracy of an instrument, such as the theodolite, with the navigating and computing ability of the mobile robot. An emitter, such as for air or light or liquid or powder, is affixed to an under carriage of a mobile robot to perform work or provide lines or marks on a floor or surface with a minimum of error and labor costs. When used as a marking system, it can be provided with several color inks, paints or dyes so that different concerns, e.g. walls, equipment, plumbing, etc., can each be marked with different colors to preclude confusion.
The robot is self propelled by battery power under the control of a computer and/or navigation system. The computer is programmed to store all desired coordinates which may be loaded, by designing points and arcs of interest to the engineer, contractor, artist, designer, grounds keeper, or other interested party, using a floppy disc, RS 232 port, or a keyboard. The robot executes the program to travel over the coordinates or locations where work is to be performed or markings are to be made on a surface. The work is performed or the markings are applied as the robot traverses the programmed path of travel or while it is stationary. The robot is provided with a theodolite, inclinometer, sensors, etc. for alignment, location and navigational purposes. To preclude errors associated with changes in direction, a "lift and turn" means is provided that raises the propulsion means above the surface being traversed for slippage free, accurate and sharp intersections when changing from an old direction of travel into a new direction of travel.